Facebook said it was investigating the allegations ‘as a matter of urgency’.
Photograph: Dominic Lipinski/PA

Facebook has fired a security engineer after he was accused of stalking women online possibly by abusing his “privileged access” to data, raising renewed concerns about users’ privacy at the social network.

The controversy, which came to light after the employee allegedly called himself a “professional stalker” in a message to a woman he met on Tinder, is particularly bad timing for Facebook, which announced this week that it is launching an online dating feature while it continues to battle a major privacy scandal in the US and the UK.

Facebook confirmed to the Guardian that the employee was terminated, but it did not provide any details on his position or the data he may have accessed, saying in a statement it was “investigating this as a matter of urgency”.

The allegations emerged on Sunday in tweets from Jackie Stokes, founder of the cybersecurity consultancy Spyglass Security, who said she learned that “a security engineer currently employed at Facebook is likely using privileged access to stalk women online”.

Stokes, who did not immediately respond to a request for comment, posted a screenshot of text messages in which the man said that he was “more than” a security analyst, writing: “I also try to figure out who hackers are in real life. So professional stalker … so out of habit have to say that you are hard to find lol”.

The woman reportedly replied: “Is that what you’re currently doing? Trying to internet stalk me?”

Stokes, who said she was not the recipient of the messages, later tweeted that “many Facebook employees” had reached out to her, and she praised them for “deft handling of a dicey issue during a time when words and actions matter more than ever”.

“It’s everyone’s issue when someone uses … possible privileged access to the biggest social media network of our time, and privilege of working in infosec [information security] ... to lord it over potential partners,” Stokes tweeted.

Alex Stamos, Facebook’s chief security officer, who gave a speech about safety at the company’s annual developer conference on Tuesday, said in a statement: “It’s important that people’s information is kept secure and private when they use Facebook. It’s why we have strict policy controls and technical restrictions so employees only access the data they need to do their jobs – for example to fix bugs, manage customer support issues or respond to valid legal requests. Employees who abuse these controls will be fired.”

The company also said that access to sensitive data was logged and audited, and that when workers attempted to view this information they saw a policy warning requiring them to confirm that access was necessary. Facebook further said it had automated systems designed to detect abuse. The company has not commented on whether this engineer’s actions were ever flagged.

The controversy resembles a major scandal at Uber in 2016, when a former forensic investigator at the company testified that employees regularly abused the company’s “God view” feature to spy on the movements of high-profile politicians, celebrities, personal acquaintances and ex-partners.

The news broke just as the Facebook CEO, Mark Zuckerberg, revealed that the site was launching a dating app for the social network meant to rival sites like Tinder and Match.com. In unveiling the new service in a speech at the San Jose conference, Zuckerberg said: “We’ve designed this with privacy and safety in mind from the beginning.”